A need exists for a process to treat metal and similar materials of manufacture to increase the structural characteristics of the metal and similar materials. For example, when manufacturing tools, tool components, machinery, engine parts, wear surfaces, and like articles made from various steels and materials used for high wear applications, the common practice is to subject the steel to one or more thermal process treatments. This is performed either before or after formation of the steel, so as to modify the properties of at least the exterior of the components. These treatments can provide the articles with greater strength, enhanced conductivity, greater toughness, enhanced flexibility, longer wear life, and other similar benefits.
A number of thermal type processes are known in the metallurgical arts to enhance the properties of manufacturing materials, such as steels and the like. One widely used class of such metallurgical processes generally known as quenching typically involves forming an article of the desired metal containing material and then rapidly lowering the temperature of the article, followed by a return of the article to ambient temperature. The problem with the current processes, controlled or not, is the formation of residual stress in the material. This results in stressing the material and even possibly fracturing the material, rendering it useless.
A further enhancement process for manufacturing materials, such as steel, involves the formation of a nitride containing layer on the surface of an article of the metal containing material that hardens the material by forming nitrides such as metal nitrides at or near the surface of an article. The formed nitride surface layer can include extremely hard compounds containing nitrides such as CrN, Fe2N, Fe3N, and Fe4N. The formed nitride layer tends to create compressive stresses that can lead to distortions in the article being treated.
A need exists for a thermal process that can be modified depending upon the specific material being treated and that does not create secondary stresses commonly associated with cryogenic and thermal temperature changes. The current art describes single wave processes that concentrate on the cryogenic target temperature and possibly one positive range temperature. The focus of the current art on the cryogenic target temperature does not give any regard to the material being treated. The cryogenic phase causes stresses in the metal, and the subsequent heat process also causes stresses in the material. The prior art has done little to deal with these secondary stresses.
A need exists for multi-wave thermal treatments in which the target temperatures are dictated by the material being treated.
A need has long existed for a thermal process to treat a metal or article of manufacture to improve its structural characteristics.
The present embodiments meet these needs.
The present embodiments are detailed below with reference to the listed Figures.